Research On Wireless Optical Communication System

FSO (Free Space Optical Communication) is a digital communication system transmitted by laser or optical plus in the atmosphere. It is also called"Wireless Optical Communication"or"Wireless Optical Network". FSO both has microwave and laser communication's advantages. Further more, it is structured with some inimitable characters such as unlimited bandwidth, no frequency admission, low cost, strong anti-jamming, good transmission secrecy, ease and speed of deployment and so on. Compared with the former broadband connection, these advantages can easily solve the"last mile"question of broadband network when FSO begin to be researched. More and more research organization and network merchandise focus on FSO. Now FSO has been used in commercial network successfully with 2.5Gbps speed rate and its speed rate can reach 160Gbps in the laboratory. Its maximal communication distance is 4-5km.Developed with the high sensitivity receptor and advance communication electronic device, as well as network increasing recently, the research on FSO achieves a new climax. This paper based on the 155Mbits/s FSO system designed by our laboratory and it introduces the system principle, modular function and signal flow. It analyses the atmosphere channel influence, optical T/R devices and environmental effect then research on the factors which affect the FSO system. Afterwards, the dissertation estimates the system parameter such as transmitting power, BER, receiving sensitivity and analyses their relationship. At the end, the author brought forward some suggestions to improve system performance for designing better FSO in the future.